import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

/**
 * Created by ScorpionOrange on 2016/09/27.
 * A panel with buttons to pop up three types of color choosers
 */
public class ColorChooserPanel extends JPanel{
    public ColorChooserPanel(){
        JButton modalButton = new JButton("Modal");
        modalButton.addActionListener(new ModalListener());
        add(modalButton);

        JButton modelessButton = new JButton("Modeless");
        modelessButton.addActionListener(new ModelessListener());
        add(modelessButton);

        JButton immediateButton = new JButton("Immediate");
        immediateButton.addActionListener(new ImmediateListener());
        add(immediateButton);
    }

    /**
     * This listener pops up a modal color chooser
     */
    private class ModalListener implements ActionListener{
        public void actionPerformed(ActionEvent event){
            Color defaultColor = getBackground();
            Color selected = JColorChooser.showDialog(ColorChooserPanel.this,
                    "Set background", defaultColor);
            if(selected != null){
                setBackground(selected);
            }
        }
    }

    /**
     * This listener pops up a modeless color chooser.
     * The panel color is changed when the user clicks the OK button.
     */
    private class ModelessListener implements ActionListener{
        private JDialog dialog;
        private JColorChooser chooser;

        public ModelessListener(){
            chooser = new JColorChooser();
            dialog = JColorChooser.createDialog(ColorChooserPanel.this, "Background Color",
                    false /* not modal */, chooser,
                    //Lambda式表达
                    event -> setBackground(chooser.getColor())
                    /*
                    new ActionListener() {
                        @Override
                        public void actionPerformed(ActionEvent event) {
                            setBackground(chooser.getColor());
                        }
                    }
                    */
                    , null /* no Cancel button listener */);
        }

        public void actionPerformed(ActionEvent event){
            chooser.setColor(getBackground());
            dialog.setVisible(true);
        }
    }

    /**
     * This listener pops up a modeless color chooser. The panel color is changed immediately
     * when the user picks a new color.
     */
    private class ImmediateListener implements ActionListener{
        private JDialog dialog;
        private JColorChooser chooser;

        public ImmediateListener(){
            chooser = new JColorChooser();
            //Lambda式表达
            chooser.getSelectionModel().addChangeListener( event -> setBackground(chooser.getColor()));
            /*
            chooser.getSelectionModel().addChangeListener(new ChangeListener() {
                @Override
                public void stateChanged(ChangeEvent event) {
                    setBackground(chooser.getColor());
                }
            });
            */
            dialog = new JDialog((Frame) null, false /* not modal */);
            dialog.add(chooser);
            dialog.pack();
        }

        public void actionPerformed(ActionEvent event){
            chooser.setColor(getBackground());
            dialog.setVisible(true);
        }
    }
}
